The present invention, in some embodiments thereof, relates to mechanical waves and, more particularly, but not exclusively, to a method and system for generating mechanical waves, useful, e.g., for the locomotion of autonomous vehicles and/or fluids.
The ability to move through long, flexible and curved tubes has long been a challenge for engineers since numerous applications can benefit from a reliable solution. This ranges from medical applications for treatment and diagnosis to sewer pipes, gas pipes and power plants.
In search for a solution, a number of locomotion types of propulsion have been developed, which pull at the distal end of the lumen rather than pushing at the proximal end. Examples in non-medical applications include crawling vehicles and spider-like robots, such as are described in U.S. Pat. Nos. 6,824,510 and 5,090,259.
In medical applications the most common solution is that of the inch worm type, that advances by means of peristaltic motion, such as is described, for instance, in U.S. Pat. Nos. 6,764,441, 4,176,662, 5,090,259, 5,662,587, 6,007,482 and 5,364,353. Another type of medical application device is described in U.S. Pat. No. 6,702,735. An additional solution is one which uses motion hydraulically generated close to the tip, such as is described in U.S. Published Application No. 20050033343.
Another type of self-propelled system is a robot that employs low frequency, non-vibratory, traveling waves as described in U.S. Published Application No. 20030029257, and in Li et al., 2003, “Analysis of traveling wave locomotion of snake robot,” in Robotics, Intelligent Systems and Signal Processing, 2003. Proceedings 2003 IEEE International Conference on, 365-369 vol. 1. A snail-like robot is disclosed in U.S. Published Application No. 20070079997 and in Chan et al., 2005, “Building a better snail: Lubrication and adhesive locomotion,” Physics of Fluids, vol. 17.
Also of interest are U.S. Pat. Nos. 3,221,702, 3,154,043, 3,066,637 and 3,623,566, and U.S. Published Application No. 20060172625, which are directed to the use of slow non-vibratory traveling waves to propel vehicles, and U.S. Pat. Nos. 6,029,294 and 3,964,316 which are directed to wave generators for therapeutic use and ocean waves simulator, respectively.
Additional background art includes E. Setter and I. Bucher (2011) “Flexural vibration patterning using an array of actuators,” Journal of Sound and Vibration, vol. 330, 1121-1140; R. Gabai and I. Bucher, 2009, “Excitation and sensing of multiple vibrating traveling waves in one-dimensional structures,” Journal of Sound and Vibration, vol. 319, 406-425; S. Ueha and Y. Tomikawa, 1993, “Ultrasonic Motors: Theory and Applications, with contributions from M. Kurosawa and N. Nakamura,” Oxford, Clarendon Press; Jean-François et al., 1998, “On the generation and identification of traveling waves in non-circular structures—application to innovative piezoelectric motors,” Smart Materials and Structures, vol. 7, 337; A. Minikes and I. Bucher, 2003, “Noncontacting lateral transportation using gas squeeze film generated by flexural traveling waves—Numerical analysis,” Journal of the Acoustical Society of America, vol. 113, 2464-2473; and Minikes et al., 2004, “Levitation force induced by pressure radiation in gas squeeze films,” Journal of the Acoustical Society of America, vol. 116, 217-226.